Phosphogypsum-sludge combined curing treatment method

Abstract

The invention discloses a phosphogypsum-sludge combined curing treatment method. The method can combine curing treatment for sludge and industrial waste phosphogypsum produced in civil engineering and hydraulic engineering. The method comprises the following implementation steps: a, measuring the water content of the phosphogypsum, water content of the sludge and clay content; b, fragmentizing the phosphogypsum; c, mixing the phosphogypsum and the sludge; d, adding a curing agent into the mixture; and e, shelving the mixture. The phosphogypsum-sludge mixed aggregates after curing treatment can be used as an earthwork stuffing for paving roads, filling dams and the like, and also can be used as solid wastes to be piled or directly embedded so as to save large amount of heap site selection charge and anti-seepage treatment charge; therefore, the method has large economic benefit and environmental benefit.

Description

technical field [0001] The invention relates to a phosphogypsum-silt joint solidification treatment method, which can mix and solidify industrial waste phosphogypsum and sludge generated in civil engineering and water conservancy projects into general solid waste, and the cured product after treatment can be used as engineering waste. Filling can also be directly landfilled. The utility model belongs to the technical field of industrial waste treatment and environmental protection. Background technique [0002] 1. Phosphogypsum [0003] Phosphogypsum is the waste residue discharged from the ammonium phosphate plant and calcium hydrogen phosphate plant in the process of producing phosphate fertilizer and phosphoric acid. The main component of phosphogypsum is calcium sulfate dihydrate (CaSO 4 2H 2 O), its content is about 70%. In addition to calcium sulfate, phosphogypsum also contains undecomposed phosphate rock, unwashed phosphoric acid, calcium fluoride, iron aluminum ...

AI Technical Summary

Problems solved by technology

At present, most of the dredged silt is disposed of by throwing mud, which occupies a large amount of land, and due to the poor permeability of the dredged silt, it is difficult to reuse the occupied land in a short period of time, thus increasing the project cost while occupying the land; The heat treatment method is to convert the dredged silt into building materials by heating and sintering. This method has small processing capacity and high cost, and is difficult to be popularized and applied on a large scale; the chemical solidification method is to add cement-based solidification materials to the silt. Perform agitation and mixing, thereby changing the properties of the sludge

Since the water content in the sludge is often high, especially the water content of the dredged sludge of rivers and lakes is generally higher than the liquid limit, the addition of curing agent is relatively large, which makes the cost of this treatment method relatively high. For large-scale sludge treatment Undoubtedly, the project cost will be greatly increased, and the higher the moisture content of the sludge, the better the curing effect will often not be achieved.